Flexibility is critical

No. of words Subject Deadline date Status
1792 Nucor Steel 2008-02-29 Original draft
Article type Success story, EcoSystem partner
Industry Metals and Mining, Petrochemical
Solution(s) SCADA
Product(s) InTouch, Historian, System Platform
Partner(s) InSource
Title Global steel industry leader improves efficiency with intelligent historian
Steel production is a costly and capital-intensive process and the highly competitive nature of the steel industry
intensifies the need to maximise asset utilisation, minimise downtime and remain flexible in order to respond to changing
market conditions.
Though the importance of this iron/carbon
alloy hasn’t changed, the way it is produced
produced has been revolutionised. One of
the world’s leading steel producers, Nucor
Steel, employs the latest technological
advances – including electric arc furnaces
run by production and performance
management solutions from Wonderware, a
business unit of Invensys – to maintain its
position at the forefront of the industry.
“We live in a worldwide economy now,” said Dennis Boyd, of Nucor. “So it’s important that we stay on the leading edge of
technology, both in how we control our furnaces and in how we collect data from them.” As supervisor of the melting area
electrical systems at Nucor’s mill in Berkeley, South Carolina, Boyd helped revamp the mill’s control systems with
Wonderware industrial control platforms. With competitive pressures growing in the global steel market, Boyd and his
colleagues wanted to make sure they were getting as muc h capacity as possible from their operation and solidifying the
company’s market position.
Flexibility is critical
The melting area of a steel mill is one of the harshest industrial environments in the manufacturing world. As
temperatures soar to 1700ºC – almost one-third of the surface temperature of the sun – the manipulation of raw
materials weighing hundreds of tons places severe strain on equipment and control systems.
The majority of the world’s carbon and alloy steel production uses electric arc furnaces, which are fired primarily with
scrap steel. At Nucor’s Berkeley mill each load consists of 180 tons of metal, about 80 percent of which is recycled scrap.
Once loaded into the furnace, 1,200 volts at 160,000 amps melts the raw material. Impurities float to the top and are
removed, leaving 165 to 170 tons of pure liquid metal. Carbon and alloys are then added to the mixture to add tensile
quality and produce the required grade of steel. Once it’s determined to be perfect, the molten mass is transferred to the
casters where it is molded into sheets of differing thicknesses and widths to meet specific customer orders.
Flexibility in this environment is a key challenge as equipment disruptions occur frequently and components must be
replaced. The organisation must also be prepared to respond to rapidly changing market conditions. By providing a clear
picture of what’s happening within the process, the chosen software solutions deliver this flexibility.
“One of the issues we deal with a lot, is the rapid changes we need to make,” said Mike Higgins, Level 2 Automation
Engineer, Nucor Steel Berkeley. Throughout the implementation of the new system, Higgins was responsible for
programming PLCs and managing the supervisory control system. “Our mill is dynamic, our company is dynamic and our
shop is dynamic. We are always trying to make changes to improve our process and we needed a system that would
allow us to do that as quickly as possible. The less time we spend doing programming, the more time we have to focus
on improvements and raising our total profits for the company.”
According to Higgins, the Berkeley mill has relied on
Wonderware’s industry-leading InTouch supervisory control
and visualisation software, since it opened in 1997. But the
mill outgrew the trending and analysis capabilities of the
existing InTouch application and needed to take its data
collection and analysis efforts to the next level. With the
need for an advanced trending tool to help identify and
eliminate problems that caused downtime becoming acute,
Nucor managers turned to InSource Solutions –
Wonderware’s regional Value Added Reseller – and asked
for a better way to collect and trend data. The only caveats:
the new system had to work with the Wonderware
applications the mill already had in place and it had to
deliver a thin client that could withstand the extreme nature
of the production floor. InSource suggested updating and
building on the InTouch application already in place with
Wonderware’s IndustrialSQL Server historian (now part of
the Wonderware System Platform) and Application Server.
The IndustrialSQL Server real-time plant historian puts the intelligence in Wonderware’s plant intelligence solutions,
delivering the data – both current and historical – that helps the melt shop team to do the detailed analysis and trending
and has enabled them to identify and eliminate the problems that cause downtime.
Thanks to Invensys’ unique ArchestrA software architecture on which the Application Server is built, Nucor was able to
centralise all the data from the different furnaces in the melt shop, providing tight integration regardless of its source. The
ArchestrA architecture is built on the latest Microsoft .NET and Windows Server technologies and industrialises these
platforms to offer a unified environment that enables the lowest integration and life-cycle costs.
The Application Server provides a unified environment for visualisation, plant history, device communications and
automation application integration. Additionally, it provides a common control and analysis capability and a facility for
making rapid changes to improve production processes.
Of particular value to Nucor Steel Berkeley, ArchestrA technology allows the use of standardised Application Objects for
faster engineering. This means that new equipment can be added or removed from the mixture more easily than before.
In an environment like the melting area of a steel mill, where equipment has a short life-cycle, this is of critical
importance.
“Before we got up and running with Application Server and the IndustrialSQL Server historian, it would take days to add a
new piece of equipment to the control system,” said Higgins. “Now I can do that in a matter of minutes.”
Important and immediate benefits
“One of the biggest benefits we saw was the elimination of downtime,” said Boyd. A common problem experienced in the
melting area involved errors in the melting process that resulted in holes being burned in the sidewalls of the furnaces or
the roof over them. These holes can be caused by a number of different failures, including an arc deflection, an arc flare
or blowback from a co-jet – which blasts pure oxygen into the reaction to increase the temperature. Each of these errors
causes the energy that should be passing through the scrap steel charge to be directed at the sidewall, blasting a fissure
that will take hours – and possibly even days – to repair.
“We use sensors to track the temperatures on the side of the furnace,” added Boyd. “We were able to collect and track
this much more accurately and come up with more sophisticated control processes.” Specifically, he said, this enabled
Nucor to do two things: “Right off it allowed us to alarm and shut down before we got holes. We’ve all but eliminated the
occurrence of these holes since we got enough trending data from the system that saved 2-5% productivity just through
elimination of downtime. This also allowed us to power the furnace down rather than shutting it off altogether, resulting in
a 5-10% gain in average power, which is directly proportional to productivity.”
Reduced downtime and increased productivity was
only the start of the benefits experienced by Nucor
Berkeley following the implementation. The new
system has also had a dramatic impact on the
quality of daily executive reporting. Prior to
deploying the new system, operations data was fed
directly from the PLCs on the shop floor into the
centralised plant-wide data control system where a
custom ‘C’ application would reformat it into the
database. This meant that three disparate sets of
the data were required and they weren’t always
consistent.
The open .NET architecture of the Application
Server allowed Mike Higgins and his team to
completely bypass the old system and feed data
directly from the InTouch control system into the
IndustrialSQL Server historian and then into the
plant-wide data collection system.
Metrics from the day-to-day operation, such as the number of tons charged into each load, the temperature in the
furnace and the amount of time the furnaces take to operate are collected and analysed each day to identify
opportunities to improve processes – and with the Application Server, managers are confident that the information they
are using is accurate.
Higgins said that; “The IndustrialSQL Server historian is something we’ve been looking for. We had got to the point
where we knew we needed to make improvements to our data collection and analysis. We would visit other mills and we
were way behind what other people were doing and now we are light years ahead. We went from being the butt of the
spear to being its tip.
“Almost immediately after introducing the IndustrialSQL Server historian, we were able to see rapid, immediate feedback
on our data and processes. We started by collecting data which we used as a basis to predict failures such that we can
now schedule preventive maintenance to minimise downtime. We are also able to track what happens at each step in
the production process, sampling the steel at different stages to make sure that each batch is going to meet the grade
and quality demands of our customers.”
Each year, the Nucor Steel mill in Berkeley, South Carolina, produces more than 2,500,000 tons of rolled sheet steel
and 1,000,000 tons of steel beams and girders in twenty different grades, depending on customer requirements. The
steel is then shipped to customers who either reprocess it and resell it or turn it into finished goods, such as refrigerators
and automotive parts. Thanks to Wonderware solutions, Nucor Steel Berkeley is doing this more efficiently and profitably
than ever before.
“The steel industry is a very harsh environment,” said Boyd. “Everything is temporary. Nothing is permanent. We see
equipment destroyed and replaced on a daily basis. We needed a system that would enable us to make those changes
without reinventing the wheel on a daily basis. Wonderware delivered that system and I would recommend it to anybody
who is looking for a way to improve their process, speed up programming changes and increase profits.”